Method for evaluating a pollution characteristic of a soil sample

ABSTRACT

A device for evaluating at least one pollution characteristic of natural soils contaminated by hydrocarbon compounds, said device comprising a first heater heating said sample in a non-oxidizing atmosphere, a measuring device determining an amount of hydrocarbon compounds released after feeding the sample into said first heater, a sample transfer device transferring the sample from the first heater into a second heater operating in an oxidizing atmosphere, a CO 2  measuring device determining CO 2  contained each effluent discharged from the two heaters, said CO 2  measuring device measuring continuously the CO 2  throughout the heating cycle of the first and the second heaters and including a device measuring CO contained in each effluent discharged from the two heaters, a temperature controller controlling the temperature of samples waiting to be fed into said heating means, and a device determining the pollution characteristic.

This application is a divisional application of Ser. No. 08/747,758,filed Nov. 13, 1996, now U.S. Pat. No. 5,786,225.

FIELD OF THE INVENTION

The present invention relates to a method and to a device fordetermining at least one pollution characteristic of a natural soilpotentially or really contaminated by pollutants, notably hydrocarbonsand/or derivatives.

BACKGROUND OF THE INVENTION

With a view to a better understanding, it should be reminded that:

during an accidental or chronic discharge (for example pipelinebreakage, tightness loss of a storage means, for example a vat or atank) or after the shutdown of old industrial sites, a certain amount ofhydrocarbon compounds can infiltrate into soils, which leads to thepollution of all or part of said soil,

knowledge of the pollutant type (gasoline, kerosene, gas oil, lubricant,chlorine derivatives, etc.) as well as knowledge of the extension inspace and in time of the pollution is of great significance for peoplein charge of diagnosis studies, environmental impact studies andpolluted soil rehabilitation. It is in fact well known that therehabilitation techniques used depend on the type of pollutants.

It is therefore very important to be able to determine quickly thenature of the pollutants and the amount of soil to be treated, thatdirectly depends on the extension of the pollution in depth as well asat the surface. Determination of the degree of pollution of a soilallows to evaluate the volumes of ground to be treated, to determine thebest treating methods and thus the costs corresponding to theimplementation thereof.

It thus appears that systematic analysis of samples of potentially orreally polluted soils allows to make quickly a diagnosis concerning thenature and the extent of the pollution, as well as the main associatedrisks (contamination of a groundwater table for example).

Knowledge of such information allows to optimize operations ofrehabilitation of contaminated sites from the diagnosis stage onwards.Long and costly laboratory analyses, without being completelysuppressed, are limited to the necessary minimum amount complementingthe information systematically collected by means of the methodaccording to the present invention.

The ROCK-EVAL method developed by the claimant is notably described indocuments U.S. Pat. Nos. 4,153,415; 4,229,181; 4,352,673; 4,519,983, aswell as French patent application FR-94/08,383. This method, which isfast, practically automatic, has been developed for characterizingmother rocks or reservoir rocks and the hydrocarbons they contain.

However, this method and the device are not suited to characterizeprecisely the various hydrocarbon cuts that can be contained in soilspolluted by such products.

The present invention is thus an improvement on the ROCK-EVAL techniqueallowing to characterize precisely the pollutants, notably of thehydrocarbon type and/or derivatives (chlorine, sulphur compounds, . . .), contained in a polluted soil.

SUMMARY OF THE INVENTION

The present invention relates to an improved method allowing fastevaluation of at least one pollution characteristic of natural soilsfrom a sample of said soil, first heated in a non-oxidizing atmosphere,then in an oxidizing atmosphere according to several temperature risestages. The method comprises at least the stages as follows:

a) the temperature of the sample is quickly raised to a firsttemperature value T₁ ranging between 80 and 120° C. for a determinedperiod (t₁ -t₀),

b) from the first temperature value, the temperature of the sample israised to a second temperature value T₂ below 200° C. according to atemperature gradient ranging between 2 and 30° C./min, and thistemperature T₂ is maintained for a determined period (t₃ -t₂),

c) the temperature is raised from the second value to a thirdtemperature value T₃ below 500° C., according to a temperature gradientranging between 10 and 40° C./min,

d) the temperature of the sample is raised from the third value to afourth value T₄ at most equal to 850° C.,

e) at least four quantities Q₀, Q₁, Q₂, Q₃ representative of the natureand of the amount of hydrocarbon compounds contained in said sample aredetermined from the previous four stages,

f) after raising the temperature to the fourth value T₄, the residues ofsaid sample are burned in an oxidizing atmosphere from a temperatureabove 350° C. to a temperature at most equal to 850° C., according to atemperature gradient ranging between 20 and 50° C./min,

g) a quantity Q₄ representative of the amount of residual organic carbonafter the four heating stages is determined,

h) at least one pollution characteristic of said sample is deduced fromthe five quantities Q₀, Q₁, Q₂, Q₃ and Q₄.

The quantity Q of pollutant can be evaluated according to the formula asfollows:

    Q=Q.sub.0 +Q.sub.1 +Q.sub.2 +Q.sub.3 +kQ.sub.4

with k ranging from 10 to 11.5.

At least one function relating at least one quantity can be determinedfrom the group made up of Q₀, Q₁, Q₂, Q₃ and Q₄, and the type "a", "b","c" or "d" of the pollutant can be distinguished according to at leastone specific value of the function for a given sample.

The type "a", "b", "c" or "d" of the pollutant can be distinguished bymeans of at least one of the specific ratios as follows:

for a pollutant of type "a", the ratio Q₀ /(Q₀ +Q₁ +Q₂) ranges between0.5 and 1 and the ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) is close to zero,

for a pollutant of type "b", the ratio Q₀ /(Q₀ +Q₁ +Q₂) ranges between0.05 and 0.5 and the ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) is close to zero,

for a pollutant of type "c", the ratio Q₀ /(Q₀ +Q₁ +Q₂) is close tozero, and the ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) ranges between 0 and 5,

for a pollutant of type "d", the ratio Q₀ /(Q₀ +Q₁ +Q₂) is close tozero, and the ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) is above 10.

The invention also relates to a device for evaluating at least onepollution characteristic of natural soils contaminated by hydrocarboncompounds, from a sample of said soils placed in a boat, said devicecomprising a first means for heating said sample in a non-oxidizingatmosphere, means for measuring the amount of hydrocarbon compoundsreleased after feeding the sample into said first heating means, meansfor transferring the sample into a second heating means in an oxidizingatmosphere, means for measuring the amount of CO₂ contained in theeffluents discharged from the two heating means, said CO₂ measuringmeans comprising a measuring cell for measuring continuously the CO₂throughout the heating cycle of the first and of the second heatingmeans, and including means for measuring the amount Of CO₂ contained inthe effluents discharged from the two heating means. The device includesmeans for determining the pollutant type, for example means forcalculating a particular function relating at least one of theQuantities Q₀, Q₁, Q₂, Q₃ and Q₄.

The device can include means for controlling the temperature of theboats waiting to be fed into said heating means.

The temperature control means can comprise at least one of the followingelements: a ventilation, a circulation of a cooling fluid, aninsulation.

The boats can include seal means.

The device can comprise means for opening the boats prior to feedingthem into the heating means, for example on the loading and transfer armor on the piston for loading the boat into the oven.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will be clear fromreading the description hereafter given by way of non limitativeexamples, with reference to the accompanying drawings in which:

FIG. 1 diagrammatically shows the composition of a soil polluted byvarious hydrocarbon cuts,

FIG. 2 describes the means for implementing the method according to theinvention,

FIG. 3 shows the various sample heating stages as a function of time,

FIG. 4 shows the form of an example of a record of Quantities Q,

FIGS. 5A, 5B, 5C and 5D illustrate an example of characterisation of thepollutants.

DESCRIPTION OF THE INVENTION

FIG. 1 diagrammatically illustrates an example of composition of anatural soil sample contaminated by various types of pollutants.

At least the following four main zones can be distinguished:

zone "a" mainly represents the amount of light hydrocarbon compounds ofboiling point below 230° C., such as gasoline, kerosene type cuts and/orlight halogenated compounds. In this zone, the number of carbon atoms ismainly below 12. In the present description, the compounds of this zonewill be referred to as compounds of type "a";

zone "b" mainly represents the amount of hydrocarbon compounds ofboiling point mainly ranging between 230° C. and 400° C., such as "gasoil" type cuts and/or polychlorobiphenyl type halogenated compounds,etc. In this zone, the number of carbon atoms mainly ranges between 13and 25. In the present description, the compounds of this zone will bereferred to as compounds of type zone "c" mainly represents the amountof hydrocarbon compounds of boiling point ranging between 400 and 550°C., such as heavy petroleum cuts, lubricating oils, etc. In this zone,the number of carbon atoms mainly ranges between 25 and 40. In thepresent description, the compounds of this zone will be referred to ascompounds of type "c";

zone "d" mainly represents the amount of hydrocarbon compounds ofboiling point substantially above 550° C., such as distillationresidues, whose number of carbon atoms is mainly above 40. In thepresent description, the compounds of this zone will be referred to ascompounds of type "d".

Each one of zones a, b, c and d is thus characterised by main compoundsin major amount according to the definition above. However, pollutantsalso containing other compounds of substantially different boilingtemperature or of a different number of carbon atoms in relation to whatis defined for a given zone may be classified in said zone since they donot modify the characterisation according to the invention.

The object of the method according to the present invention is to allowto distinguish and simultaneously to quantify the various types ofpollutants contained in a soil sample in view of their belonging to oneof the zones defined above. During a diagnosis survey of a pollutedsite, soil samples are taken in various places and at various depths inorder to be characterised by means of the present method in thecorresponding device. The characterisation results allow soil pollution"profiles" to be drawn up by differentiating thus the polluted groundsfrom the preserved grounds, as well as the nature and the gravity of thepollution.

FIG. 2 describes the device allowing the method according to theinvention to be implemented. It comprises an automaton that performs themeasurements and a PC (personal computer) that controls the automaton,serves as an interface with other computers, manages the analyses,allows real-time visual display of the results and uses control and testsoftwares.

The measuring device comprises two micro-ovens, a sample changersupplying them with boats and an analysis system consisting of one orseveral specific detectors, for example a flame ionization detector(FID) or an electron capture detector (ECD), and of infrared cells (IR).These elements are connected to electronics and to a fluid circuitmanaged by the PC and by the automaton software.

In FIG. 2, reference number 1 shows the heating assembly suited for thepyrolysis of sample 2 placed in a boat 3 borne by a piston 4.Displacement means 5 for moving the boat feed the sample into the innerspace 6 of the oven. The displacement means can be pneumatic, hydraulicor electric control jacks. Reference number 7 schematizes the linedelivering the carrier fluid for sweeping the products pyrolysed in theoven. This fluid (nitrogen or helium) sweeps the sample by flowingthrough the piston. Distribution means (not shown) lead the carrierfluid to the upper part of the oven to perform a back-sweeping drain ofthe inside of the oven when the piston moves back, for example at theend of the pyrolysis process in order to transfer the sample and/or toload another sample. In fact, the influence of oxygen on the organicdeposits on the walls of the pyrolysis oven can generate oxygencompounds CO₂ and CO that can hinder the analysis.

A temperature probe 8 measures the temperature at the level of the boatbottom, thus very close to the sample. The measuring point of anothertemperature probe 9 is in the wall of the well, at the level of theupper position of the boat, a position corresponding to the optimumheating point. The temperature programming of the oven is preferablyperformed by means of probe 8, which allows good control and knowledgeof the pyrolysis temperature of the sample. Temperature probe 9 is usedto control the temperature of oven 1 when the oven is open and piston 4has moved down to extract boat 3 and to replace it by another. Thetemperature of oven 1 can thus be maintained at a value close to thevalue determined for the next pyrolysis, which prevents too great a heatloss.

Heating assembly 1a is similar to heating assembly 1 in every respect.This assembly 1a is intended for the operation of oxidation of a sample,generally after pyrolysis. The identical elements bear suffix "a". Itmay be noted that the fluid injected through line 7a is air in thiscase.

Heating assemblies 1 and 1a both have temperature regulation meansallowing a temperature gradient programming that can reach or evenexceed 850° C.

Reference number 10 shows the flame ionization detector FID delivering asignal S representative of the amounts of hydrocarbon products releasedfrom the sample during heating. Arrow 11 shows the transfer of signal Sto the digitizing means. The flame ionization detector FID mustwithstand high temperatures, and it therefore requires jointswithstanding such conditions without creeping or desorbing products thatmight cause the base line to drift.

Its linearity and its sensitivity, combined with a very slight base linedrift, guarantee high precision in the analysis of hydrocarbons.

The analog signal will be digitized and smoothed with the maximum numberof points depending on the programming rate.

An electron capture detector ECD can be used instead of the FID orplaced in parallel to another FID type detector, which then requires adistribution means for the flows coming from the oven, for example apilot valve suited to withstand the high temperatures of the flows.

Line 12 leads part of the flow to means 13 intended for continuousanalysis of the amounts of CO₂ and of CO produced by pyrolysis of thesample. At the outlet of the pyrolysis oven, the divided flow is heatedto at least 360° C. in order to prevent heavy product condensations.

Line 12a leads at least part of the oxidation flow to means 13A intendedfor continuous analysis of the amounts of CO₂ and of CO produced.

Distribution means 14 and 14a allow to use only one or other of the CO₂and CO analysis means for the pyrolysis or oxidation flow. Preferably,for operational time saving reasons, means 13 and 13a will be allocatedto only one heating means. The continuous analysis means are for exampleinfrared detectors.

The infrared cells IR, being specific to a gas, can measure continuouslythe CO₂ and CO concentrations in the effluents during pyrolysis andoxidation. They allow to win access to new information such as thepresence and the amount of various carbonates, the maximum releasetemperatures, the peak shapes, the transition between the inorganiccarbon and the organic carbon and the distribution of each oxygencompound in the various cracking reactions of the organic matter.

The length of the detector cells depends on the maximum sensitivityrequired, therefore on the minimum concentration to be measured. Itdepends on the amounts of CO₂ or CO produced by the sample (therefore onits mass), on the analysis time (therefore on the heating conditions)and on the flow rate of the carrier gas that is a diluting factor.

The cell analyzing the CO₂ measures maximum concentrations of 2% for aflow rate ranging from 50 to 200 ml. This bracket is linearized on fourautomatic-change ranges:

range 1: 0 to 2% CO₂

range 2: 0 to 1% CO₂

range 3: 0 to 0.5% CO₂

range 4: 0 to 0.25% CO₂

The cell analyzing the CO measures maximum concentrations of 1% underthe same conditions as the CO₂ cell. The four ranges are:

range 1: 0 to 1% CO

range 2: 0 to 0.5% CO

range 3: 0 to 0.25% CO

range 4: 0 to 0.125% CO.

The signals obtained from cells IR are re-shaped in order to obtaincurves with the same attenuation, digitized like the FID signal.

The device also comprises flow purification means 15 and 15a.

Arrows 16 and 16a refer to the transfer of measurements to theelectronic digitizing means 16b.

Furthermore, the device includes a sample changer 17 whose arm 18 issuited to shift the boat containing a sample between three possiblepositions: the pyrolysis oven, the oxidation oven and storage support19.

The sample changer has simplified mechanics so that displacements can beperformed by means of electric stepping motors. Any controlpossibilities are thus available and they only depend on the workingsoftware. For example, it will be possible to load the boats only in theoxidation oven for particular studies. Another possible application willconsist in subjecting samples to a heat treatment in an oven and inrecovering them afterwards on the boat or storage support 19 in order toanalyze them according to the desired cycle.

The boat support is not linear but circular: it exhibits the shape of acarousel, which saves spaces and allows Quicker access to the desiredboat by means of a forward or reverse motion of the changer. A numberassigned to each location allows passage of the samples to be programmedin the chronological positioning order of the boats on the changer aswell as according to either the various cycle or analysis types or toanalysis priorities.

The environment of boat support 19 is thermally controlled by thermalregulation means 20 so that the boats waiting to be loaded aremaintained at a temperature preventing the start of a vaporizationcycle, the boats being on the support. Means (23) 20 can include meansof thermal insulation from the heat released by the oven and/or localcooling means, for example a coolant circulation (24), or any othersystem, e.g., a ventilation element (25).

The boats can comprise caps 21 intended to prevent evaporation of anamount of light pollutant, which might alter the evaluationmeasurements. In this case, the boats are prepared on the site. The caphas to be perforated prior to feeding the boat into the oven. FIG. 2diagrammatically shows means 22 connected to the loading arm that canfor example strike the cap as the loading arm seizes a boat. Anothersolution, among others understandable to technicians, can consist inperforating the cap while the boat moves towards or into the oven.

FIG. 3 shows the particular temperature sequences leading to theoperation of pyrolysis of a polluted soil sample. There are at leastfour such temperature sequences. At the time t₀, the sample is fed intothe oven already heated to the initial temperature T₁. This temperaturevalue is below 120° C., preferably close to 80° C. The ascent of thesample in the oven is relatively fast, which allows the sample to bebrought very quickly to the internal temperature of the oven. This firstheating stage (conventionally called isothermal) lasts for example for atime t₁ -t₀ of about 10 minutes. From time t₁, the temperature of theoven is raised to a temperature T₂ below 200° C. and preferably close to180° C. The temperature rise time t₂ -t₁ is for example of the order of5 minutes so as to obtain a temperature gradient ranging between 2 and30° C./min, but preferably of about 20° C./min. The second heating stagelasts for a time t₃ -t₂ of about 15 minutes for example. In a programmedpyrolysis stage starting from time t₃, the temperature rise ispreferably close to 20° C./min up to the temperature T₃ corresponding tothe time t₄. The value of this temperature T₃ is about 400° C.,preferably close to 370° C. Pyrolysis proceeds until the temperature T₄at most equal to 850° C. is reached. The programmed temperature risebetween t₄ and t₅ is not imposed, the only important factor being thetime spent for measurements and the temperature rise capacity of theoven. Temperature T₄ can thus be reached with the same temperaturegradient as previously between t₃ and t₄ or with a different temperaturegradient.

The pyrolysis residues are thereafter burned in the oxidation ovenbetween 350° C. and 850° C., at a gradient ranging between 25 and 50°C./min, preferably between 35 and 40° C.

FIG. 4 shows quantities representative of all the polluting hydrocarbonsthat can be contained in a polluted soil according to the compositionshown in FIG. 1.

It can be seen that, under the heating conditions described in FIG. 3,the polluted soil sample can give, during a heating program, a firstpeak Q₀, a peak Q₁, a peak Q₂ and a peak Q₃ respectively bearingreference numbers 30, 31, 32 and 33. Peak Q₄, bearing reference number34, corresponds to the stage of oxidation of the pyrolysis residues.

Peaks Q₀, Q₁, Q₂ and Q₃ correspond to the release of the hydrocarboncompounds contained in the soil sample in view of the presence ofpollutants according to classifications a, b, c and d. It may bereminded that:

type "a" mainly corresponds to the light hydrocarbon compounds whoseboiling point is below 230° C., such as gasoline, kerosine type cutsand/or light halogenated compounds. In this zone, the number of carbonatoms is mainly below 12;

type "b" mainly corresponds to the hydrocarbon compounds whose boilingpoint mainly ranges between 230° C. and 400° C., such as "gas oil" typecuts and/or the polychlorobiphenyl type halogenated compounds, etc. Inthis zone, the number of carbon atoms mainly ranges between 13 and 25;

type "c" mainly corresponds to the hydrocarbon compounds whose boilingpoint ranges between 400 and 550° C., such as heavy petroleum cuts,lubricating oils, etc. In this zone, the number of carbon atoms mainlyranges between 25 and 40;

type "d" mainly corresponds to the hydrocarbon compounds whose boilingpoint is substantially above 550° C. and whose number of carbon atoms ismainly above 40.

Of course, according to the nature of the pollutant or pollutantspresent in the soil, characterisation may comprise only three, two oreven one of these four peaks.

Specifically calibrated calculation means determine the respectiveamounts of the various pollutant types according to the shape, to theamplitude of said peaks and to the organic carbon remaining afterpyrolysis.

In fact, the pyrolysis of heavy products generally involves theformation of coke. The coke is thereafter burned in the second oxidationoven of the device, and the CO₂ and the CO produced are measured andsummed, which gives a peak representative of a characteristic quantityQ₄ (34). The percentage of residual organic carbon in the sample,referred to as residual organic carbon Rc remaining after pyrolysis, asopposed to the pyrolysed organic carbon Pc, is thus determined.

Elementary analyses performed on the coke show that its organic carboncontent is 90% on average.

The various quantities Q₀, Q₁, Q₂, Q₃ and Q₄ are expressed in milligramper gram.

It is from these quantities and from specific ratios between thesevalues that the extent and the nature of the contamination found in thesoil can be judged.

It has been determined that certain specific functions of the fivequantities Q₀, Q₁, Q₂, Q₃ and Q₄ allow to define the pollutant types andamounts. In particular, it has been determined that most of thepollutants can be characterised from two functions of the type f(Q₀, Q₁,Q₂ and g(Q₀, Q₁, Q₂, Q₃ and Q₄).

More precisely: function f can preferably have the form as follows: Q₀/(Q₀ +Q₁ +Q₂), and g preferably the form as follows: (Q₃ +Q₄)/(Q₀ +Q₁+Q₂)

For a pollutant of type "a", the ratio Q₀ /(Q₀ +Q₁ +Q₂) ranges between0.5 and 1 and the ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) is close to zero.

For a pollutant of type "b", the ratio Q₀ /(Q₀ +Q₁ +Q₂) ranges between0.05 and 0.5 and the ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) is close to zero.

For a pollutant of type "c", the ratio Q₀ /(Q₀ +Q₁ +Q₂) is close to zeroand the ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) ranges between 0 and 5.

For a pollutant of type "d", the ratio Q₀ /(Q₀ +Q₁ +Q₂) is close to zeroand the ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) is above 10.

FIGS. 5A, 5B, 5C and 5D show four examples of application of the methodto soil samples polluted by various hydrocarbon types. Graphs 35, 36, 37and 38 represent the quantities associated with various pollutinghydrocarbons. The pyrolysis program according to FIG. 3 is as follows:

T1=100° C. for 10 minutes;

T2=180° C. (20° C./min gradient);

2-minute isotherm at 180° C.;

T3=370° C. (20° C./min gradient);

T4=850° C. (20° C./min gradient);

oxidation between 350 and 800° C. (35° C./min gradient).

FIG. 5A illustrates a pollution due to a jet fuel, i.e. an aviation fuelbelonging to type a. In this example, the ratio Q₀ /(Q₀ +Q₁ +Q₂) isclose to 0.86 and the ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) is close to zero.

FIG. 5B illustrates a pollution due to an automotive gas oil belongingto type b. In this example, the ratio Q₀ /(Q₀ +Q₁ +Q₂) is close to 0.17and the ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) is close to zero.

FIG. 5C illustrates a pollution due to a lubricating oil belonging totype c In this example, the ratio Q₀ /(Q₀ +Q₁ +Q₂) is close to zero andthe ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) is close to 0.4.

FIG. 5D illustrates a pollution due to a coal distillation residuebelonging to type d. In this example, the ratio Q₀ /(Q₀ +Q₁ +Q₂) isclose to zero and the ratio (Q₃ +Q₄)/(Q₀ +Q₁ +Q₂) is close to 13.

We claim:
 1. A device for evaluating at least one pollutioncharacteristic of soil samples contaminated by hydrocarbon compounds,said device comprising a first heater heating a soil sample in anon-oxidizing atmosphere, a measuring device determining an amount ofhydrocarbon compounds released after feeding the soil sample into saidfirst heater, a sample transfer device transferring the sample from thefirst heater into a second heater operating in an oxidizing atmosphere,a CO₂ measuring device determining CO₂ content of each effluentdischarged from said first and second heaters, said CO₂ measuring devicemeasuring continuously the CO₂ content throughout heating by the firstand the second heaters and including a device measuring CO content ofeach effluent discharged from the two heaters, a temperature controllercontrolling the temperature of soil samples waiting to be fed into saidfirst heater, and a device determining the pollution characteristic. 2.The device as claimed in claim 1, wherein said temperature controllercomprises art least one of a ventilation element, a cooling fluidcirculation element or an insulation element.
 3. The device according toclaim 1, wherein the sample is placed in a boat.
 4. The device asclaimed in claim 3, wherein the boat comprise a seal.
 5. The device asclaimed in claim 4, comprising an opener opening the boats prior tofeeding them into the first heater.
 6. The device according to claim 1,wherein the measuring device determining the amount of hydrocarboncompounds is a flame ionization detector or an electron capturedetector.
 7. The device according to claim 1, wherein the CO and CO₂measuring devices are at least one infrared detector cell.